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[INTRODUCTION]

Steganography is the method for hiding secret messages in other messages, such that the secret’s very existence is concealed. Generally the sender writes an message and then conceals a secret message on the same piece of paper. Throughout history tricks have been made use using invisible inks, tiny pin punctures on selected characters, minute differences between handwritten characters, pencil marks on typewritten characters.....and of course IMAGES[remember DA VINCI? and the debut MONALISA SMILE]

Steganography is the art or practice of concealing a message, image, or file within another message, image, or file.[Its based on your incapability of persiving small changes,So beware---This speaks "What you see is Not what you Believe"]

But we are going to discuss about the art of hiding message in an Graphic image[LOL,this is the age of computers not the 14 the century Canvass painting]

This is done by replacing the least significant bit of each byte of the image with the bits of the message.This wouldn't change the graphic image appreciably as most graphics standards specify more gradations of color than the human eye can notice......and the message can be stripped out at the receiving end.
You can store a 64-kilobyte message in a 1024 × 1024 grey-scale picture this way

[OVERVIEW OF THE GRAPHICS BACKGROUND]

A pixel is a single point in a graphic image. Graphics monitors display pictures by dividing the display screen into thousands (or millions) of pixels, arranged in rows and columns. The pixels are so close together that they appear connected.

The number of bits used to represent each pixel determines how many colors or shades of gray can be displayed. For example, in 8-bit color mode, the color monitor uses 8 bits for each pixel, making it possible to display 2 to the 8th power (256) different colors or shades of gray.[[[For simple monochrome images, one bit is sufficient to represent each dot, but for colors and shades of gray, each dot requires more than one bit of data.]]]

The density of the dots, known as the resolution, determines how sharply the image is represented. This is often expressed in dots per inch (dpi) or simply by the number of rows and columns, such as 640 by 480.

The encryption of a plain text message is done by selecting the last bit, in a 8 bit pixel word, and replaces it with a single bit from the cipher text. That change is so insignificant that it does not alter the appearance of the image as viewed on a computer display.

[EXAMPLE]

Now lets get practical,we will hide the character 'S' is an eight (8) bit byte which is represented in binary form as 01010011.

The series of nine pixels from the image, three pixels each made up of three pixels RGB(red, blue and green) are used for the needed eight bits, with one left over to be used for the first bit in the next character of the message.

Not bad but you left a lot unexplained in parts. for example, the side note \"(Leave it alone,Dude..Don\'t need it)\" is a bit unexplained is it not?
I believe you are using that note there because that would be a ninth bit you don\'t need.

But onto other portions. for example, the line \"pixel 3 red = 255 = 11111111 hide 1 = 11111111 = 255\"
Why is it we hide one? Hide one what? This is very confusing on my part, if it has something to do with other complicated binary I\'m sorry but I don\'t get it.

Another part is the \"hide 0\" why do we hide zero? this makes no sense whatsoever and confuses me greatly.

Anyways, some greater explanations on your part would be greatly appreciated.

Also, check out the CDC\'s(not Center for Disease Control :) ) site.
They have a program that can automagically hide and find all kinds of stuff in images. It\'s open source and it\'s called CameraShy. It also uses 128-bit AES encryption. Nice app or what?

We are here just encrypting the letter S
So we dont need the last bit...
S====01010011
We scan the BINARY FROM right,[you can also do it the other way,then the decryption method would be different]and take each bit,
which we substitute in the least significant bit of the RGB pixels...\"hide 0 means hiding 0 in the least significant bit of the pixel

Anyway, this is interesting but it goes to say that this is a very reversible method though, and that anyone can take two pictures which appear the same, and check the binary of them.

Answer to a question someone posed earlier, if we had 11111111 and we wanted to add a 1 to it, we would just leave it alone, since the digit we are adding is already 1, so 10000000 would turn to 10000001. Although it would be wrong to call it adding, call it more... editing a bit. if the 1 is already a 1, we count it as a 1, whilst if it was a 1 and is now a 0, we would count it as 0.

PoP_ is perfectly correct...in his explanation.
**\"that this is a very reversible method though, and that anyone can take two pictures which appear the same, and check the binary of them.\"

This is just a demonstration,in practice we encrypt the message and then stegano it...
\"There are numerous Pics which look alike\"over the net,you are going to scan through all of them????

darthvader -->Suppose after a word you always have a space which have a binary equivalant,thus we store that[the binary eqivalent of space] in the same fashion.hence while decryption the message gets into the normal form.[and remember each is 8 bits only]

I personally had to read this through a couple of times to understand it completely.
I agree you could have been a little more detailed here and there, but overall you were successful in sharing an interesting idea with the rest of us. Thanks, bluesun!